import java.math.BigInteger;
import java.util.Scanner;

public class Array_1_6_11 {
    public static void main(String[] args) {
        BigInteger a,b;
        Scanner input=new Scanner(System.in);
        a=input.nextBigInteger();
        b=input.nextBigInteger();
        System.out.println(a.subtract(b));
    }
}